Composition of matter



Patented May 9, 1950 COMPOSITION OFMATTER Zeno W. Wicks, Jr., New York, N. Y., assignor to Interchemical Corporation, New York, N. Y., a

corporation of Ohio No Drawing. Application September-11, 1947, Serial No. 773,523

This invention relates to compositions of matter'especially adapted for use in dispersing pigments for incorporation into pigmented compo sitions such as paints, varnishes, lacquers, enamels, inks and the like.

In the manufacture of pigmented coating compositions it is frequent practice to first disperse the pigment in a vehicle to form a pigmented paste before incorporating it into the paint, varnish, lacquer, or ink vehicle. This dispersion of pigment in vehicle is generally accomplished by grinding the pigment and the appropriate amount of vehicle in a suitable mixer such as a pebble mill, ball mill, roller mill, or dough mixer, and the vehicle employed is commonly referred to as a grinding vehicle. Essential properties of these grinding vehicles are: compatibility with the vehicle into which they will be subsequently incorporated, low viscosity, good wetting properties, non-reactivity with pigments, paleness of color, should not discolor at relatively high baking schedules if the resulting coating is to be baked, should not show tackiness in an airdried film, and should be free from skinning tendencies.

Due to the large variety of protective coating compositions that are manufactured and the necessarily large variety of vehicles used in formulating them, it has been necessary for the paint, varnish and lacquer manufacturers to keep in stock a large variety of pigment grinding vehiclesi. e. a grinding vehicle to be used with each type of paint, varnish and. the like that is to be produced. For example, linseed oil has been used as a grinding vehicle for pigmenting pastes for oil base paints but these pastes cannot be used with alkyd resin or nitrocellulose formulations. Likewise, a varnish containing oilmodified alkyd resins and linseed oil has been used as grinding vehicle for pigments for incorporation in alkyd base compositions but this vehicle cannot be used with oleoresinous or lacquer formulations.

The protective coating industry has long desired a vehicle which can be used to make pigment pastes that are compatible with all the types of vehicles used in formulating protective coatings, such as siccati've oils, oleores'inous varnishes, synthetic resin compositions, lacquers, etc. In addition to being compatible with the various vehicles used in formulating coating compositions, the grinding vehicle should possess the other desirable properties for grinding vehicles that are listed hereinabcve. Accordingly, it is an object of the prese invent??? to 12 Claims. (Cl. 106239) produce grinding vehicles that can be used to make pigment pastes for incorporation into a large variety of coating composition vehicles. Other objects of the invention will become apparent as the descriptionof the invention proceeds.

The grinding vehicle of the present invention consists essentially of varnishes cooked from hard resins and polyesters of polyhydric alcohols containing five to ten hydroxyl groups in which not less than one and not more than two of the hydroxyl groups of the polyhydric alcohol are esterified with a polyunsaturated water-insoluble fatty acid (1. e. drying oil fatty acids). The polyester oils are substantially non-drying, but will dry in the presence of other drying and semidrying oils. Thus the varnish vehicles made from such oils will not skin or dry of themselves, but when incorporated into other drying or semidrying vehicles, they do not deter the drying of these other vehicles. In this respect, therefore, these novel varnish vehicles are ideal grinding media for pigments.

The oils used in the grinding vehicle varnishes can be defined as synthetic polyester oils obtained by substantially completely esterifying polyhydric alcohols with at least two different acids. The polyesters have the general formula X. n-Y, Z.

where R is a residue of a polyhydric alcohol containing 5' to 10 hydroxyl groups, for instance, using dipentaerythritol the residue would have formula Likewise, X represents an acid radical of a watersoluble monocarboxylic aliphatic acid containing at least two carbon atoms, e. g. the acetate radical; Y represents either an acid radical of a water-soluble monocarboxylic acid containing at least two carbon atoms (i. e. same as X),or Y can be a monocarboxylic acid containing an aromatic nucleus which constitutes at least about '50 per cent by weight of the molecule, e. g.

benzoate or phenylacetate; Z represents an acid radical of poly-unsaturated fatty acid containing 10 or more carbon atoms or mixtures of these (i. e. a drying oil fatty acid or mixtures of the acids obtained by hydrolyzing a drying oil); :0, y and 2 represent the number of moles of X, Y and Zgroups'respectively, neither x nor y being j in air dried or baked films.

less than the number of hydroxyl groups in the polyhydric alcohol and 2 being not less than 1 nor more than 2; and where, in the polyester molecule as a whole, the total number of acid radicals is substantially equal to the number of hydroxyl groups in the polyhydric alcohol.

The polyester oils used in the invention are formed by esterifying a polyhydric alcohol containing five to ten hydroxyl groups with from about 1 to 2 mols of polyunsaturated water-insoluble acid, and the remaining hydroxyl groups with at least one acid of the group including watersoluble fatty acids and acids containing an aromatic nucleus in the molecule. soluble polyunsaturated fatty acids include: sorbic acid, eleostearic acid, linoleic acid, and the like, or mixtures of such acids, for instance, dehydrated castor oil fatty acids, linseed oil fatty acids, soya oil fatty acids, fish oil fatty acids and the like, which may contain some water-insoluble saturated and monounsaturated acids.

Water-soluble fatty acids that may be used in- .clude acetic acid, propionic acid, butyric acid, isobutyric acid, and substitution products of these in which the substituent is unreactive during the process of preparing the polyesters, e. g.

.chloro acetic acid. Also. other water-soluble acids such as levulinic acid are operable.

Monocarboxylic acids of the group containing an aromatic nucleus that are preferred contain only. one aromatic nucleus in the molecule, such as, ,benzoic acid, toluic acids, phenylacetic acid. phenoxyacetic acid and the like. The aromatic nucleus should constitute at least about 50 per cent by weight of the molecule in order that the aromatic nature of the acid can be imparted to the polyester. Also, substitution products of these acids (e. g. mono and polychlorobenzoic acids) can be used provided that the substituent groups are unreactive during the preparation of esters. For this reason the use of acids containing nitro groups is not desirable.

The preparation of the polyesters used in the present invention can be accomplished by any of v,the usual methods of preparing sters, as by heating the reactants to a suitable temperature in the presence or absence of esterification catalysts.

The grinding vehicle varnishes made in ac- Examples of water-in-' cordance with the invention may be used alone,

but preferably they are cut to not less than i .total non-volatile content with a relatively high boiling hydrocarbon solvent. In this manner the yiscosity of the vehicle is conveniently regulated.

For most grinding procedures a viscosity of one to about five poises will be desired.

Due to the drying properties of the novel polyesters, when they are used in the presence of other drying vehicles, they do not show tackiness grinding vehicles made from these polyesters, being substantially non-drying alone, give pigment pastes that are free from skinning.

Also,- the grinding vehicles of the present invention are non-reactive with pigments and have good wetting properties. For the best wetting properties the vehicle should be prepared from a polyester oil having an acid number of the order of 1 to 10. 7

The manner in which the vehicles are prelong in oil length. Depending for the most part Furthermore, the V upon the particular resin and polyester oil used, the varnishes should preferably be from about 15 to about 45 gallon oil length.

0f the hard resins, e. g. copal, Congo, kauri, phenolic resin, amber, rosin, limed rosin, ester gum, maleated rosin esters, and other modified rosin derivatives, commonly used in cooking oleoresinous varnishes, the maleated rosin esters containing 8 to 12% of maleic modification and having melting points of the order of 130-170 C. (Hercules drop method) are preferred.

The manner of practicing the invention will be more fully understood from the following examples in which the parts are by weight unless otherwise stated.

Example I A mixture of 31.9 parts of soy fatty acids, 9.2 parts of benzoic acid and 20.9 parts of sorbitol (commercial grade containing about 84 sorbitol) was heated to 230 C. until esterification was complete (about four hours). The resultant product was refluxed with 38 parts of acetic anhydride for about two hours and then the acetic acid and excess acetic anhydride wasremoved by vacuum distillation. The oil left as residue had an acid number of 1.2 and a viscosity of 3.7 poises. This oil was readily compatible with hard varnish resins.

Example II Using the oil prepared in Example I a 25 gallon oil length varnish was prepared by heating it at 225 C. with about half of its weight of an 8-l2% maleated rosin ester resin (melting point, Hercules drop method, 130-140 0.). This varnish was then cut to non-volatile content with high flash petroleum naphtha (boiling point 165-175 C.) to give a grinding vehicle of acid value 4.3 and a viscosity of 4.3 poises. 'The var nish was then used to make pigment pastes by dispersing an appropriate amount of the desired pigment in the varnish vehicle in conventional manner as by grinding on a 3-ro1l mill. These pigment pastes could then be incorporated in various types of vehicles to give coating compositions having properties equal to or better than similar compositions prepared from pigment pastes containing the various specific grinding vehicles for each type of composition that have been used heretofore.

Typical pigment paste compositions prepared using the varnish vehicle of Example II are:

. Parts A. Ferrite yellow 60 Vehicle 40 B. Chrome green 50 Vehicle 50 The pigment was dispersed in each instance by grinding in a three-roll mill. These pigment pastes showed no livering and no skinning at 158 F. for hours. 7

'As a test for the pigment pastes prepared using the grinding vehicle described above, the pigment pastes were dispersed in several vehicles which was thought to provide the severest test for the pastes. For this purpose a pure phenolic spar varnish was taken as an example of an oleoresinous varnish; a relatively short oil (29% soya fatty acids) modified phthalic alkyd and a phenolic modified alkyd were used as typical alkyds; and a straight run gum (kauri); nitrocellulose lacquer was used as a test lacquers Although these formulations do not cover the broad field of coating formulations thoroughly it was believed that ?-h-ie1es.

ent formulations containing the same grinding *vehicle with actual formulations of the same type containing-a specific grinding vehicle irr-eaChfor- *mulation, it was found "that test-enamel formusince these particularones had proved most difficult in obtaining compatibility'between pigment paste-and base vehicle that they would furnish the severest testfor the grinding vehicle prepared in Example'II. "In'the test the formulations were "the same except for thegrinding vehicle: used to make the pigment pastes.- Formulationscontaim ing each of the abovevehicles and'pigment paste prepared according .toExample II were prepared and the vehicle of the paste was found to be satisfactorily compatible with each of the base ve- Also, upon comparing these-four differlations were equal or-better in gloss and award hardness properties than the formulations used in actual practice and containing-specific grind- "ing vehicles for compatibilitywith "eachpfr-the types of base vehicles. Thus-the use of'grinding vehicles prepared according "to the present invention dispenses' with'the necessity of keeping numerous vehicles in stock, that is, aspecific grinding vehicle'for'each type of formulation to 'be manufactured.

Example III The polyester oil obtained in Example I was cooked into a 37.5 gallon varnish by heating it at 225 C. withone-third of its weight of an'8 to 12% maleated rosinester resin. 'After' reducing the varnish to 80% non-volatile content with high flash petroleum naphtha (boiling point 165- 175 (2.), the varnish was used as a grinding vehicle formaking'pigment pastes. The pigment pastes were tested in'a, manner similar to that and 4.5 moles acetic aci'dwas prepared by,:a;procedure similar toth-at in Example I. For the purpose of calculating molar, ratios .of the molecular weight of polypentaerythritol was considered to be :the'average of the .molecular-weights0f1diand tripentaerythritol. A3715 gallon varnish'was -prepared byheating this polypentaerythritolroil at 225 C. with one-thirdpf its weightof an 28-12% maleated rosin ester resin (melting p drop method, 130-140" 0.). This varnish was then reduced to 80% non-wolatiletcontent with high flash petroleum naphtha (boiling point ';165-1'75 C.) and usedas a grinding .VBhiClBlill making pigment pastes. Thefpastes'were readily dispersible in and compatiblewithioleoresinous,

aalkyd and -lacquer formulations. .z-Filmsof these .final compositions formed 'zon metal and 'air- 7 dried or bakedhad tgoodrjgloss'iand hardness.

Example V The polyester oil'of Example'I wascookedinto a varnish by heating it'at 225C. Withpne-third --oiits weight'of an 842% maleatedrosin'ester resin (melting point, Hercules drop method, 152-168 C.). The varnish was then cut to 80% non-volatile content and used as a grinding ve- ""hicle for preparing pigment pastes on "3-1011 -mil1. "The resulting pastes were: suitably :compat'ible with oleoresinous varnishes, .alkyds :an'd "nitrocellulose lacquers. Enamels "and lacquers prepared using the pastes had good air dry and baking properties and gave films 'having good *adhesion, 1 gloss and hardness.

Sincenum-erous modifications of the invention canbe practiceditis intended that the scope'of the'inv-ention be limited only by thevalidscope cf the appended claims.

I claim:

1. Avarnish vehicle suitable foruse in-grindil'lg pigments for incorporation into oleoresinous varnishes, alkyds, lacquers, and the like, consisting essentiallyof not less'than 75 parts f 2a to 45 gallon'length hard varnish resin-poly.- ester oil varnish, theapolyesteroil "comprising-1a substantially completely esterified polyhydric alcohol having the general formula where R is 1a'polyhydricalcohol-residue ofan aalcoholcontainingB to 10 hydroxyl groups, Xis :an acid radical ofa water-soluble monocarboxylic aliphatic *acid containing at least two carbon :atoms'yis the acidradical of anacid' of the-group consistingr'of water-solublemonocarboxylic acids "containing-at least two carbon atoms-andmcnocarboxylic acids containing a mononuclear aromaticring, Z iszan acid radical of polyunsaturated leng chain'fatty acid, and :L, y and-.2 equal-the number-of moles of X, Y and Zrespectively, where neither nor y is less than l d the sum of as, y and e, and a is not less than l nor more'th-an 2, and. not more than parts of a hydrocarbon solvent. for-the varnish.

2. A varnish vehicle suitable for use iii-grinding pigments for incorporation into oleoresinous varnishes, alkyds, lacquers and the like, consisting essentially of not less than 75 parts of a 15 to gallon length maleated rosin ester resin-polyester oil va-rnish, the polyester oil comprising a substantially completely esterified polyhydric a-lcohol havingthe general formula where R is :a polyhydric alcohol residue of an alcohol containing 5 to 1-0 hydroxyl'groups,.X.is an acidradical ofa water-soluble monocarboxylic aliphatic acid containing at least two carbon atoms, an'acid radical of an-acid of the group consisting of water-soluble monocarboxylic taliphatic acids containing at least two carbon-atoms and monocarboxyli'c acids containing a mononuclear aromatic ring, Z is an acid radical of a polyunsaturated long chain fatty acid, and'x, y-and z equal the number of'molesof. X, Y and Z respectively, where neither'xhnor y is less-than the sum of 3:; y and e, and z is not lessthan 1 nor more than 2, "and not more than 25 partsof .a hydrocarbon solvent for the varnish.

3. A varnish vehicle suitable for use in grinding pigments for incorporation into oleoresinous varnishes, alkyds, lacquers and the like, consisting essentially. of-notless than parts of..a .15 to.45 gallon lengthmaleatedrosin ester resin-polyester .oil varnish, the polyester oil comprising a :sub-

stantially. completely .esterified polyhydrical'cohol having the general formula where R, is a polyhydric alcohol residue :of an alcohol containing 5 to 10 hydroxyl groupsfX is an'acid'radicral of a water-soluble monocarboxylic Iialiphatic 'acid containing at least two carbon atoms, Y is the benzoate radical, Z is an acid radical of'a polyunsaturated long chain fatty acid, and any and 2 equal the number of moles of X, Y and Z respectively, where neither :1: nor y is less than the sum of :v, y and z and z is not less than 1 nor more than 2, and not more than 25 parts of a hydrocarbon solvent for the varnish.

4. A varnish vehicle suitable for use in grinding pigments for incorporation into oleoresinous varnishes, alkyds, lacquers and the like, consisting -.:essentially of not less than 75 parts of a 15 to 45 gallon length maleated rosin ester resin-poly- ..iester oil varnish, the polyester oil comprising a substantially completely esterified polyhydric alcohol'having the general formula where R is a polyhydric alcohol residue of an alcohol containing 5 to hydroxyl groups, X is the acetate radical, Y is the benzoate radical, -Z is an acid radical of a polyunsaturated long chain fatty acid, and at, y and 2 equal the number of moles of X, Y and Z respectively, where neither :c nor y is less than 6 the sum of .B, y and z, and z is not less than 1 nor more than 2, and not more than 25 parts of a hydrocarbon solvent for the varnish.

5. A varnish vehicle suitable for use in grinding 'pigments for incorporation into oleoresinous varnishes, alkyds, lacquers and the like, consisting essentially of not less than 75 parts of a to 45 gallon length maleated rosin ester resin-polyester oil varnish, the polyester oil comprising a substantially completely esterified polyhydric alcohol having the general formula where R is the residue of sorbitol, X is an acid radical of a water-soluble monocarboxylic aliphatic acid containing at least two carbon atoms, Y is an acid radical of an acid of the group consisting of water-soluble monocarboxylic aliphatic acids containing at least two carbon atoms and monocarboxylic acids containing a mononuclear aromatic ring, Z is an acid radical of the polyunsaturated long chain fatty acid, and w, y and 2 "equal the number of moles of X, Y and Z respectively, Where neither .1: nor 1; is less than the sum of :0, y and z, and z is not less than 1 nor more than 2, and not more than 25 parts of a hydrocarbon solvent for the varnish.

' I 6. A varnish vehicle suitable for use in grinding" where R is the residue of sorbitol, X is the acetate radical, Y is the benzoate radical, Z is an acid Tradical of a polyunsaturated long chain fatty acid, and w, y and z equal the number of moles of X, Y and Z respectively, where neither a: nor

is less than the sum of x, y and z, and z is not less than 1 nor more than 2, and not more than 25,- partsof a hydrocarbon solvent for the varnish.

7. A varnish vehicle suitable for use in grind;- ing pigments for incorporation into oleoresinous varnishes, alkyds, lacquers and-the like, consisting essentially of not less than parts of a 15 to 45 gallon length maleated rosin ester resin-polyester oil varnish, the polyester oil comprising a substantially completely esterified polyhydric alcohol having the general formula where R. is the residue of sorbitol, X is the acetate radical, Y is the benzoate radical, Z is the acid radical of soy fatty acid, and :c, y and 2 equal the number of moles of X, Y and Z respectively, where neither a: nor y is 'lessthan the sum of zc, y and z, and a; is not less than l-nor more than 2, and not more than 25 parts of a hydrocarbon solvent for the varnish.

8. A varnish-vehicle suitable for use in grinding pigments forincorporation into oleoresinous varnishes, alkyds, lacquers and the like, consisting essentially ofnot less than -'75 parts of a 15 to 45 gallon length maleated rosin ester resin-polyester oil varnish, the polyester oil comprising a substantially completely esterified polyhydric alcohol having the general formula where R is the residue of sorbitol, X is the acetate radical, Y is thephenoxyacetate radical, Z is the acid radical of soy fatty acid, and m, y and 3 equal the number of moles of X, Y and Z respectively, where neither a: nor y is less than the sum of :r, y and z and zis not less than 1 nor more than 2, and not more than 25 parts of a hydrocarbon solvent for the varnish. V

9. A pigment paste suitable for incorporation into oleoresinous varnishes, alkyds, lacquers, and the like, comprising a pigment dispersed in a vehicle consisting essentially of not less than '75 parts of a 15 to 45 gallon length hard varnish resin-polyester oil varnish, the polyester oil comprising a substantially completely esterified polyhydric alcohol having the general formula where R is a polyhydric alcohol residue of an alcohol containing 5 to 10 hydroxyl groups, X is an acid radical of a water-soluble monocarboxylic aliphatic acid containing at least two carbon atoms,Y is theac idradical of an acid of the group consisting of water-soluble monocarboxylic acids containing atlea'st'two carbon atoms and monocarboxylic acids containing a mononuclear aromatic ring, Z is an acid radical of polyunsaturated long chain fatty" acid, and :r, y and 2 equal the number of moles of X, Y'and Z respectively, where neither it nor yis' less than 1% of the sum of in, y and z,-an'd zis not less than. 1 nor more than 2, and nct'more than 25 parts of a hydrocarbon solvent for the varnish.

10. A pigment paste suitable for incorporation into oleoresinous varnishes, alkyds, lacquers, and the like, comprising a'pigment dispersed in a vehicle consisting essentially, of not less than '75 parts of a 15 to 45 gallon'length maleated rosin ester resin-polyester oil varnish, the polyester oil Wi -i; R i eq rhy rl l e ie re d e of, a

alcohol containing to hydroxyl groups, X is an acid radical of a water-soluble monocarboxylic aliphatic acid containing at least two carbon atoms, Y is the acid radical of an acid of the group consisting of Water-soluble monocarboxxylic acids containing at least two carbon atoms and monocarboxylic acids containing a mononuclear aromatic ring, Z is an acid radical of polyunsaturated long chain fatty acid, and a, y and 2 equal the number of moles of X, Y and Z respectively, where neither :1: nor y is less than the sum of :c, y and z, and z is not less than 1 nor more than 2, and not more than 25 parts of a hydrocarbon solvent for the varnish.

11. A pigment paste suitable for incorporation into oleoresinous varnishes, alkyds, lacquers, and the like, comprising a pigment dispersed in a vehicle consisting essentially of not less than 75 parts of a to 45 gallon length maleated rosin ester resin-polyester oil varnish, the polyester oil comprising a substantially completely esterified polyhydric alcohol having the general formula where R is a polyhydric alcohol residue of an alcohol containing 5 to 10 hydroxyl groups, X is the acetate radical, Y is the benzoate radical, Z is an acid radical of a polyunsaturated long chain fatty acid, and m, y and 2 equal the number of moles of X and Y respectively, where neither :0 nor y is less than the sum of x, y and z, and z is not less than 1 nor more than 2, and not more than parts of a hydrocarbon solvent for the varnish.

12. A pigment paste suitable for incorporation into oleoresinous varnishes, alkyds, lacquers, and the like, comprising a pigment dispersed in a vehicle consisting essentially of not less than '75 parts of a 15 to gallon length maleated rosin ester resin-polyester oil varnish, the polyester oil comprising a substantially completely esterified polyhydric alcohol having a general formula where R is the residue of sorbitol, X is the acetate radical, Y is the benzoate radical, Z is an acid radical of a polyunsaturated .long chain fatty acid, and x, y and 2 equal the number of moles of X, Y and Z respectively, where neither an nor 1 is less than the sum of at, y and a, and 2 is not less than 1 nor more than 2, and not more than 25 parts of a hydrocarbon solvent for the varnish.

ZENO W. WIC'KS, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,077,371 Rheineckeet et al. Apr. 13, 1937 2,390,202 Burrell et al Dec. 4, 1945 FOREIGN PATENTS Number Country Date 452,138 Great Britain Aug. 10, 1936 

1. A VARNISH VEHICLE SUITABLE FOR USE IN GRINDING PIGMENTS FOR INCORPORATION INTO OLEORESINOUS VARNISHES, ALKYDS, LACQUERS, AND THE LIKE, CONSISTING ESSENTIALLY OF NOT LESS THAN 75 PARTS OF A 15 TO 45 GALLON LENGTH HARD VARNISH RESIN-POLYESTER OIL VARNISH, THE POLYESTER OIL COMPRISING A SUBSTANTIALLY COMPLETELY ESTERIFIED POLYHYDRIC ALCOHOL HAVING THE GENERAL FORMULA. 